1. Field of the Invention
The present invention relates to an integrated compressed gas fuel storage system for motor vehicles, called the Integrated Storage System (ISS), comprising a plurality of high pressure gas storage cylinders (hereinafter referred to as pressure cells), interconnected by a gas control assembly incorporating operational and safety controls all contained within a molded housing.
2. Background
Domestic oil production is declining due to U.S. oil reserves becoming more difficult to tap while demands on petroleum production escalate. Half of the U.S. oil supply is imported and the U.S. Department of Energy predicts a 60 percent deficiency by the year 2010. International oil companies relying on easily extracted foreign oil may meet the demand but at an unacceptable cost to the U.S. economy. The primary cause of the short fall is the motor vehicle. Current predictions indicate motor vehicles will proliferate globally from 500 million today to one billion by the year 2030. The solution is obvious, alternative fuels must be developed for motor vehicles.
It has been demonstrated that compressed gases such as hydrogen, propane, methane or natural gas are viable alternatives to petroleum as a fuel source for motor vehicles. Natural gas is one of the more interesting of the alternatives because it is a plentiful commodity in the United States and therefor inexpensive. As a result, more than 30,000 natural gas vehicles are currently in use in the United States. These vehicles have demonstrated low fuel costs and reduced engine maintenance while affording a significant reduction in exhaust emissions. Such vehicles have been restricted to fleet trucks, delivery vans, buses and taxis due to their limited range. The restrictions and limitations are caused by the space required for existing compressed gas fuel systems. This space penalty results in lost truck bed volume, automobile trunk volume and range. Furthermore, higher initial purchase prices are experienced due to the cost of the gas storage systems.
Compressed gas vehicle fuel systems traditionally consist of a single large cylinder or a series of smaller cylinders mechanically clamped together and rigidly mounted to the vehicle chassis. Numerous clamps, brackets, and redundant valves and safety devices are required to comply with federal law. Installation and maintenance costs are high.
An example of a contemporary compressed natural gas fuel system for an automobile is illustrated in FIG. 1. In this typical system, compressed natural gas storage cylinders reside in the trunk, taking up valuable cargo space, and numerous safety devices are redundantly incorporated throughout the fuel delivery system to insure that each tank has adequate safeguards to meet the applicable regulations. The size and/or number of tanks can be reduced, but this solution results in an unacceptable range limitation. The foregoing and related factors have hampered sales of light-duty natural gas powered vehicles and development of the industry.